Features November 2010 Issue

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New Surgical Options Expand Treatment Choices for Ankle OA

Cartilage cells can now be harvested, grown in a lab, and used to repair a painful joint—all while eliminating the risks of traditional procedures.

If you have advanced arthritis in the ankle and haven’t responded to traditional treatment, you may be a candidate for either of two relatively new procedures. One is called autologous chondrocyte implantation (ACI), the other is called matrix-induced autologous implantation (MACI), and both are supported by a growing body of clinical evidence.

In the MACI procedure, good cartilage cells are (1) taken from the ankle or knee, (2) harvested and gown into a matrix backing material, then (3) transplanted to the bone.

In the ACI procedure, the surgeon first uses arthroscopic surgery to identify the area of damage, then removes cartilage cells from the ankle or even the knee, and those cells are multiplied in a laboratory for four to six weeks. Once the cells are grown, another surgical procedure—called an osteotomy—is performed to implant the cells. MACI involves harvesting cells, growing them onto a backing material called a matrix, and transplanting the matrix to the bone. In preliminary studies, an osteotomy was not needed to transplant the matrix, eliminating the risk of tissue damage in the ankle.

"Neither procedure is for the faint of heart," says James Williams, MD, an orthopaedic surgeon at Cleveland Clinic. "The patient must fully understand and agree to what it takes to undergo these treatments and recover after the procedures have been performed. Rehabilitation takes time."

Dr. Williams also points out that ACI and MACI are more likely to be performed on younger patients (under the age of 55) because their bodies have a greater capacity to heal. A study published in the September 2009 issue of Foot and Ankle International, involving patients between the ages of 19 and 61, concluded that MACI was a reliable treatment method for osteochondral defects of the talus (the small bone between the heel bone and the lower bones of the leg). The July 2009 issue of the Journal of the American Academy of Orthopaedic Surgeons (JAAOS) reported that both ACI and MACI have proven to be successful in treating the talus.

Traditional techniques

Most patients with advanced ankle arthritis can be treated using traditional techniques—called debridement and drilling—that remove dead tissue and stimulate blood flow to the affected area. But 20-25 percent of people do not respond to these therapies and may benefit from the newer ACI and MACI procedures. Lesions that typically do not respond well to older reparative methods are usually larger, deeper, or may have a cyst-like structure.

"Both ACI and MACI show a lot of promise," says Matthew Mitchell, MD, author of the JAAOS study, "but the advantage of MACI is that an osteotomy is not necessary to successfully implant the matrix. You only need to make an incision to place the graft, which decreases the complexity of the procedure."

Cleveland Clinic’s Dr. Williams adds that patients who fit the criteria and undergo ACI usually have good intermediate results. Orthopaedic surgeons undergo specialized training to perform ACI and MACI, but trained physicians can be found throughout the U.S.

Practical applications

What is the implication of this emerging technology if you suffer from advanced ankle arthritis? It means that you should work with your doctor in managing your condition with the safest and least invasive methods possible, including exercise, modifying activities and footwear that involve the ankle, and medication. In some cases, ankle fusion (arthrodesis)—removing the worn out portion of the joint and fusing the bones into a fixed position—may be the best course.

But now you may have two more options, so if other treatments are not working, ask your doctor about ACI and MACI.